Method for manufacturing activated carbon for electrode material

Abstract

Described herein is a method for manufacturing an activated carbon for an electrode material, the method including a step of heat-treating an activated carbon material in an atmosphere containing a chlorine-containing gas, wherein the content of metal impurities contained in the activated carbon material after the heat treating step is 0.1 to 20 ppm.

The invention claimed is: 
     
       1. A method for manufacturing an activate carbon for an electrode material, the method comprising:
 preparing a carbon material; 
 carbonizing the carbon material; 
 mixing the carbonized carbon material and an activator; 
 activating the carbonized carbon material having the activator mixed therein; 
 washing and drying the activated carbon material; and 
 heat-treating the activated carbon material in an atmosphere containing a chlorine-containing gas, after the washing and drying of the activated carbon material, 
 wherein a content of metal impurities in the activated carbon material after the heat-treating of the activated carbon material ranges from 0.1 ppm to less than or equal to 20 ppm, and 
 wherein a specific surface area of the activated carbon material after the heat-treating of the activated carbon material is reduced by 20% or less in comparison to the specific surface area of the activated carbon material before the heat-treating of the activated carbon material. 
 
     
     
       2. The method of  claim 1 , wherein in the mixing of the carbonized carbon material and the activator, the activator is an alkali hydroxide and is added in a weight ratio of 1 to 5 based on the carbonized carbon material. 
     
     
       3. The method of  claim 1 , wherein the activating of the carbonized carbon material is performed at an activation temperature of 500° C. to 1000° C. 
     
     
       4. The method of  claim 1 , wherein after the activating of the carbonized carbon material, a content of the activator in the carbonized carbon material is 500 ppm or less. 
     
     
       5. The method of  claim 1 , wherein the washing and drying of the activated carbon material is performed by at least one method selected from the group consisting of acid washing, distilled water washing, and inert gas washing. 
     
     
       6. The method of  claim 1 , wherein the washing and drying of the activated carbon material comprises drying the activated carbon material at a temperature of 50° C. to 200° C. 
     
     
       7. The method of  claim 1 , wherein after the washing and drying of the activated carbon material, pH of the activated carbon material ranges from 6.5 to 7.5. 
     
     
       8. The method of  claim 1 , wherein the chlorine-containing gas comprises at least one selected from the group consisting of HCl, Cl 2 , CHCl 3 , ClO 2 , BCl 3 , SiCl 4 , CCl 4 , CHCl 3 , COCl 2 , CHCl 3 , and CH 2 Cl 2 . 
     
     
       9. The method of  claim 1 , wherein:
 the chlorine-containing gas is mixed with an inert gas to form an atmosphere, and 
 the chlorine-containing gas is included in an amount of 1 to 50% by volume in gases forming the atmosphere. 
 
     
     
       10. The method of  claim 1 , wherein the heat-treating of the activated carbon material is performed at a temperature of 500° C. to 1000° C. 
     
     
       11. The method of  claim 1 , further comprising, after the carbonizing of the carbon material:
 grinding the carbonized carbon material to an average particle size of 3 μm to 20 μm. 
 
     
     
       12. The method of  claim 1 , wherein a content of oxygen in the activated carbon material after the heat-treating of the activated carbon material is 1% or less.